Alloy steel



Patented Aug. 6, 1929.

- UNITED STATES FREDERICK C. LANG-ENBERG, OF WATERTOWN, MASSACHUSETTS.

ALLOY STEEL.

H0 Drawing.

My invention relates to the provision of a new and improved alloy, steel,;and more particularly to an alloy steel containing manganese and molybdenum.

l Heretofore, manganese steel alloys have been produced to which molybdenum was added with the result that the usual physical properties of the manganese steel were intensiiied. Steel alloys containing up to to about 3 per cent of manganese and as high as 1.25 per cent of molybdenum together with. not more than about 0.80 per cent of carbon when properly heat treated have a high tensile strength and high elastic limit.

lit is an object of the present invention to provide a steel alloy of this general'type having improved physical properties, particularly, greater ductility and higher resistance to shock while maintaining a high at tensile strength and elastic limit. p

I It is a. further object of the invention to provide a steel alloy containing manganese and molybdenum.which be molded to form sounder castings, with resulting improved physical properties, than is possible with the j ordinary 'manganesemolybdenum steel alloy. l

7 As a resultof extended investigations, I have found that the addition of zirconium in small aniounts to a manganese steel alloy, particularly one containing molybdenum, materially improves its physical properties. Higher ductility and greater resistance to shockis noticeable in particular in an steel making process. 3

The alloy steel of the invention finds application in various fields, but I have found it particularly.admirablefor the manufacture of castings for railway cars, such as bolsters andside frames. A suitable alloy steel composition for this purpose may contain from about 0.25 to about 0.45 of carbon and from about 1.25 to about 1.75

cent of manganese together with from about alloy of this type which contains a small 81':- ture. 0.25to3about 0.50 per centof molybdenum:

Application fl1ed.Ianuary 24, 1927. Serial No. 163,297.

and from about 0.15 to about 0.30 per cent of zirconium. Castings made from such an alloy steel composition, when properly heat treated, have very great resistance to shock and. at the same time are sufiiciently strong and resistant to fatigue so that they can be made much lighter than similar castings heretofore produced. I

If two manganese-molybdenum steel alloys are made of substantially the same composition except that one contains a small amount of zirconium, the one containing zirconium can be annealed or heat treated so as to give it the same elastic be subjected to dynamic or impact stresses.

On the other hand, a manganese-molybdenum alloy steel containing zirconium and which has substantially the same resistance to impact as an alloy steel of substantially the same composition without the zirconium will have a higher elastic limit and tensile strength. In fact, if it is desired to have a high elastic limit and tensile strength, the alloy of the invention may be'hea-t treated to give these properties without seriously detracting from its resistance to impact.

What I claim is:

1. An alloy steel containing substantial amount-sot manganese'and molybdenum but not morethan about 3 per cent of manganese nor more than about 1.25 per cent of molybdenum together with from about 0.10 to about 0.50 per cent if zirconium.

2. An alloy stebl. containing from about 1.25 to about 1.75 per cent of manganese and from about 0.25 to about 0.50 per cent of molybdenum together with from about 0.15 to about 0.30 per cent of zirconium. I

- 3. An alloy steel containing from about. 1.25 to about 1.75 per cent of manganese and from about 0.25 to about 0.50 per cent of molybdenum together with from about 0.15 to about 0.30pm cent of zirconium and from about 0.25

carbon.

In 'testimony whereof I afiix my signamam -e, Lineuuenne.

to about 0.45 per cent of 

